The present invention relates to a technique of biomeasurement using light for measurement of the density or density change of metabolites. The present invention particularly relates to a probe for biomeasurement by use of light for the density of metabolites in a subject's head and an optical bioinstrumentation for living body using the same.
“Medical Physics, vol. 22, No. 12, pp. 1997–2005 (1995)” and “Proceedings of SPIE, vol. 3597, pp. 230–237” have already proposed techniques for measuring a blood amount change in a cerebral cortex in accordance with brain activity at multiple points, and displaying the blood amount change as a moving image or still image (optical bioinstrumentation). These techniques employ a rectangular probe having incident optical fibers and detection optical fibers alternately arranged in square lattice configuration.
Since the above square lattice probe cannot be attached tightly to an approximately globular head without difficulty, the following proposals have been already made.    (1) Japanese Published Unexamined Patent Application No. 2001-286449 discloses a optical bioinstrumentation for living body having a branch-like part extended from a linking axis so as to fit to the shape of head.    (2) Japanese Published Unexamined Patent Application No. 2002-143169 discloses an optical bioinstrumentation for living body in which connecting portions of a lattice probe are rotatable and a holder to hold the respective probes is stretchy.    (3) Japanese Published Unexamined Patent Application No. 2002-11012 discloses a probe having square lattice filling plural areas of the head and polygonal members filled among each vertex of the lattice so as to cover the entire head.    (4) Published Japanese Translation of PCT International Publication for Patent Application No. 2002-502653 discloses an apparatus for non-destructively measuring a subject's brain tissue with probes geometrically arranged on the subject's head.    (5) Japanese Published Unexamined Patent Application No. 2004-121702 discloses a probe having 4 sets of diamond arranged incident optical fibers and detection optical fibers to cover the overall globular head, capable of displaying almost all area of a brain surface in one image.